Burglar-alarm.



L. MYERS.

BURGLAR ALARM.

APPLICATION FILED NOV. 9, 1909.

Patented Oct. 4, 1910.

2 BHEETB-SHBET 1.

L. MYERS.

BUBGLAB. ALARM. APPLIOATIQH FILED NOV. 9, 1909.

971,776. Patented 0013.4,1910.

2 QHEETS-BHEET 2.

WWW! K Maw UNITED STATES PATENT oEEicE.

LEWIS MYERS, OF NEWARK, MICHIGAN.

BURGLAR-ALARM.

To all whom it may concern:

Be it known that I, LEwis MYERS, a citizen of the United States,residing at Newark, in the county of Oakland and State of Michigan, haveinvented a new and useful BurglanAlarm, of which the following is aspecification.

This invention has reference to improvements in burglar alarms and isdesigned to provide a means whereby an unauthorized person entering theprotected area will set an alarm into operation by engaging with anattenuated strand of sufiicient strength to cause the movement of thealarm to active position even though the force operating on the strandbe sufficient to break the latter.

By the present invention a room or an entire building may be protectedagainst entrance or approach of unauthorized persons and the alarm beset into operation without the intruder being aware of havingencountered the strand.

The invention will be best understood from a consideration of thefollowing detail descripticn taken in connection with the accompanyingdrawings forming a part of this specification, in which drawings,

Figure 1 is a partially diagrammatic and partially structural view ofthe alarm mechanism to be actuated by the strand with the parts in theinoperative position. Fig. 2 is a similar view with the parts in theoperative position. Fig. 3 is a diagram illustrating the application ofthe device to the pro tection of a room. Fig. 4 is a diagram showing thearrangement of the device for the protection of a building against theapproach of intruders.

Referring to the drawings and more particularly to Figs. 1 and 2 thereis shown a pivoted arm 1 with its ends oppositely bent and at theirextremities carrying rock arms 2, 3 respectively, projecting equally onopposite sides of their pivot connections with the arm 1. The free endsof each arm 2 and 3, which arms as well as the arm 1 may be made of flatbars, are turned at right angles to the body portions of the said arms 2and 3 and there carry insulated studs 4 of conducting materialprojecting beyond one face of the arms 2 and 8 and at the other endsformed with means for the attaching of conductors 5 electricallyconnecting the conducting studs a in such manner that the stud e at oneend of the arm 2 is connected to the stud 4 at the corresponding end ofthe arm 3 Specification of Letters Patent.

Application filed November 9, 1909.

- is connected by a conductor 10 to Patented Oct. 1, 1910. Serial No.527,092.

and the studs at the other ends of these arms are also connected by aconductor In the path of each stud at is an elastic conducting finger 6mounted on a suitable block 7. One stud 1 is connected by a conductor 8to one side of a battery 9 or other source of electric current while theother side of this battery the other finger 6 engaged by the stud on theopposite end of the arm 2. The fingers 6 in the path of the studs 1 onthe arm 3 are connected one by a conductor 11 to one side of a bell 12and the other by a conductor 13 on the other side of the bell 12.

The arm 1 with the parts carried thereby as well as the battery 9 areall housed in a suitable box 1% which may be located in any desiredposition and the bell 12 may be exterior to this box. One of theconductors, say the conductor 11 includes a switch 15 so that theapparatus may be cut out of service whenever desired. Pivotally mountedwithin the box 14 is a lever 16 having one end connected by a link 17 toone side of the arm 1 while the other end of the lever is bent into aquarter turn, the lever being made of a flat bar and traversed by a rod17 surrounded by a spring 18 and extending through a bracket 19, theaction of the spring 18 being to move the lever in' a direction to causethe studs t to engage the fingers 6. The lever 16 may be locked againstthe action of the spring 18 with the latter under tension by a bellcrank lever 20 suitably mounted in the box 1a and having one end 21extending therebeyond. This end 21 receives one end of a strand 22 whichmay extend to various points liable to be entered by an intruder, itsdirection being diverted where necessary by pulleys 23. In Fig. 3 thestrand 22 is shown as traversing doors and windows, and on each side ofthe latter the strand may pass through eyes 21 and the strand at oneside of either the door or window or both may have its continuity brokenso that the ends of the strand at such point may be coupled together asby hook and eye or other suitable means and when the device is not to beoperated the portion of the strand traversing the door or window or bothmay be unhooked from the main portion of the strand and temporarilysuspended from an eye 25 at one side of the door or window. This willnot interfere with the circuit closing mechanism of Figs. 1 and 2 andwhich is housed in the box 14: since the lever 16 is positively lockedby the bell crank lever 20 and it is only a pull on the arm 21 that willcause the lever 20 to move to a position releasing the lever 16. If anintruder attempts to enter through a door or a window across which thestrand 22 is extended, the strand will be engaged by the intruder andmoved longitudinally to a sufficient extent to pull the lever 20 so thatit releases the lever 16 when the spring 18 will act to move the lever16 and through the link 17 the lever 1 into a position where the studs 1will engage the fingers 6 and so close the circuit. The strand 22 may behighly attenuated but strong enough to cause the movement of the lever20 even though the strand be ultimately broken.

In Fig. 4 the strand 22 is shown as mount ed upon short posts 26 andextending for a sufiicient distance to include a considerable area abouta building 27. If now an intruder approached the building then thestrand 22 will be engaged since it is lodged but a short distance abovethe ground but at such a height as to be surely engaged by the intruderand the alarm will be caused as before, the said alarm being maintaineduntil the lever 1 is again locked in the inactive position.

A burglar alarm to be efficient must be positively operative at alltimes and faulty connections or faulty conducting members cannot betolerated. It will be observed that in the circuit closing mechanismshown in Figs. 1 and 2 the circuit at no point traverses any pivot, butthe circuit is completed through spring fingers along which theconducting studs 1 move so tha whenever the circuit is closed there is arubbing contact which at all times positively insures good electricalconductivity.

Vhat is claimed is 1. In a burglar alarm a pivoted arm carrying contactmembers at each end electrically connected independent of the arm,elastic contact fingers in the paths of the contact members on thepivoted arm, an electric circuit completed through the said contactmembers and elastic fingers, an actuating member for the pivoted arm, alock for the actuating member for holding the pivoted arm in theinactive position, and a strand extending from the lock to the point tobe protected.

2. In a burglar alarm a pivoted arm having at each end pivoted armscarrying contact members at each end, electric conductors independent ofthe pivoted arm and connecting the contacts at the end of the firstnamed arm, elastic circuit terminals in the path of the contacts on theends of the arms carried by the first named arm, a spring controlledlever connected to the first named arm for moving the same, a latchmember for holding the spring controlled member against its normaltendency, and a strand extending from the lock or latch member to thepoint to be protected.

In testimony that I claim the foregoing as my own, I have hereto atfixedmy signature in the presence of two witnesses.

LEl/VIS MYERS.

"Witnesses WILLIAM P. Hicks, IVILLIAM A. PATTERSON.

